Tenter drier



M. sHr-:GDA

TENTER vDRIEIR April 1, 1952 2 SHEETS-SHEET l Filed Jan. 8, 1951 Af .TH

. Invenr: Michael Shegda @has ibmq @OOGOGOQOOOOOGG Q .FIH

April 1 1952 M. SHEGDA 2,591,621

TENTER DRIER Filed Jan. 8, 1951 2 sx-nzETs-sx-IEET 2 Patented Apr. l, 1952 TENTER DRIER Michael Shegda, Phil-adelphia, Pa., assigner to Proctor & Schwartz, Inc., Philadelphia, Pa., a. corporation of Pennsylvania Application January 8, 1951, Serial No. l204,945

Claims.

provements in dryers, and more particularlyl to dryers of the tenter type wherein fabric or cloth is impaled along its opposite edges upon the pins of a tenter chain and is carried thereby through the dryer.

In dryers of this type heated air or other medium generally is discharged vertically into contact with opposite surfaces of the fabric from nozzles arranged both above and below the fabric carried on the tenter chain. It is important, of course. to obtain the maximum possible production from the dryer and hence the demand continuously is to operate the dryers at higher speeds using larger volumes of drying air at .higher temperatures. The use of larger volumes of drying ai'r requires that the discharge velocity of the air be increased accordingly so that a point is reached where it is very difcult to maintain the opposite side edges of the fabric engaged upon the pins of the tenter chain.

In the past it has been attempted to 4solve this problem by discharging drying air at a substantially higher velocity against the upper surface of the fabric than against the bottom or undersurface thereof. This practice, however, defeats the purpose of the slack or tensionless drying of the fabric transversely thereof since the greater air velocity directed downwardly against the top fabric surface gives the fabric a very definite crosswise tension. In other instances resort has been made to providing rails along and above the opposite 'edges of the fabric which are'designed to hold the fabric edges down upon the tenter pins, but an arrangement such as this is objectionable because the rails leave an unsightly rub mark on the surface of the nished fabric.

With the foregoing in mind, the principal ob.. `iect of the present invention is to provide in a tenter dryer a novel construction and arrangement of the nozzles above and below the fabric which operate to discharge substantially large volumes of drying air against the upper and lower surfaces of the fabric wit-hout tending to disengage the fabric from the pins of the tenter chain and while maintaining the fabric substantially slack and free of crosswise tension.

' Another object of the invention is to provide a tenter dryer construction of the stated type embodying a novel construction and arrangement of the air nozzles therein which is operable to provide a substantially increased rate of production or capacity as compared with like dryers which do not embody this invention.

' A further object of the invention is to provide a novel drying medium nozzle construction for tenter dryers having the aforesaid'features and advantages which is of relatively simplified construction, comparatively inexpensive to manufacture and is highly effective and efficient in operation and use of the dryer.

dryer for fabric.

These and other objects of the invention and the various features and details of the construetion and operation thereof are hereinafter. fully set forth and described with reference to the accompanying drawings, in which:

Fig. 1 is a vertical sectional view longitudinally through a tenter dryer incorporating the present invention;

Fig. 2 is an enlarged transverse sectional view on line 2 2, Fig. l; v

Fig. 3 is an enlarged fragmentary sectiona view transversely of the tenter chain and the adjacent portions of the upper and lower nozzles illustrating the operation of the nozzle construction of the present invention;

Fig. 4 is a fragmentary view in plan from the underside of one of the upper discharge nozzles showing thev contour orconfiguration ofthe nozzle outlet;

Fig. 5 is a plan View from above of one of th lower discharge nozzles showing the contouror configuration of the nozzle outlet; i

Fig. 6 is a view similar to Fig. 4 showing modified construction and arrangement of the upper discharge nozzle openings, and;

Fig. '7 is a View similar to Fig. 5 showing a modified construction and arrangement of the lower discharge nozzle openings.

Referring now more particularly to the drawings, there is disclosed a conventional type tenter The dryer illustrated comprises an insulated elongated enclosure or housing I having an inlet opening 2 at one end for the fabric and tenter chain and an outlet opening 3 therefor at the opposite end. The insulated enclosure or housing I is provided with a central raised portion 4 in which are mounted suitable heating coils 5 and a blower 6 for heating and recirculating, respectively, the air or other drying medium.

Movable longitudinally through the dryer housing I are the parallel courses of a conventional type tenter chain comprising roller connected links l which travel in suitably spaced parallel rails 8 that extend longitudinally through the dryer housing I. The two courses of the chain 'I are each provided with inwardly projecting arms 9 which are provided with upstanding tenter pins I0 on which the opposite selvage edges of a fabric II are impaled, for example, in

' the manner and relation shown in Fig. 3 of the drawings.

Disposed above and below the tenter chain and fabric II carried thereby are chambers I3 and I4, respectively, which, as shown in Figs. l and 2, extend entirely transversely of the fabric II as well as substantially the entire length of the dryer I. rThese chambers I3 and I4 are supplied continually with heated drying air from the blower 6 through duct I5 and branches I6 and Il. The confronting wall portions of the chambers I3 and I4, namely, the bottom wall I8 of the upper chamber I3 and the top wall I9 of the lower chamber I4, are constructed to provide therein a plurality of nozzles and 2I, respectively, for discharging the drying medium from the chambers I3 and I4 into contact with the fabric II. As shown in Figs. 1 and 2 of the drawings, the nozzles 2B and 2I extend entirely transversely of the tenter chain and fabric II and are disposed at equally spaced intervals longitudinally thereof within the dryer housing I with the nozzles 2i) of the upper chamber I3 disposed in opposed confronting relation with respect to the nozzles 2| of the lower chamber shown in Fig. 1.

` In accordance with the present invention, the transversely extending nozzles fil of the upper chamber I3are constructed to provide an outlet or discharge opening for each nozzle having the contour or configuration shown in Fig. 4 of the drawings. Thus, each of the transverselyV extending nozzles 20 of the upper chamber I3 are constructed to provide an outlet or discharge opening which has a predetermined maximum width at its opposite lateral extremities as indicated at 22 and gradually decreases in width in opposite-directions inwardly from its ends to a point centrally of the nozzles 2t which is of predetermined minimum width.

On the other hand, the nozzles 2l of the lower chamber Irl-are constructed to provide anV outlet or discharge opening having the contour or configuration .shown in Eig. .5 of the drawings wherein the nozzle outlet opening is of predetermined maximum width at its midpoint and gradually decreases in opposite directions outwardly to a predetermined minimum width at the opposite ends of the nozzles. In the illustrated embodiment of the invention the dimensions of the maximum and` minimum widths of the discharge openings of the upper nozzles 20 are the same as the maximum and minimum dimensions of the outlet openings of the lower nozzles 2l. although this isnot essential and the relativeV dimensions of thezrespective portions of the nozzle outlet openings will be determined largely by the fabric being dried in anyY given case.

By constructing the upper and lower sets of discharge nozzles 2G and 2I as described it will be observed that theY upper nozzles 2&3 operate to discharge a greater volume of drying air from the opposite end portions of the nozzle onto the salvage .edge portions of the fabric II on the tenter chains while a lesser volume of air is discharged. onto the central portions of the upper surface of the fabric I ,I from the central portions of the nozzles 2G. Conversely, the lower nozzles 2l operate todischarge a greater volume of air upwardly against the central portion of theunderside ofthe fabric-while a lesser volume of air is discharged from the ends of the lower nozzles against the underside of the selvage edge portions of the fabric II.

The effect of this isV shown in Fig. 3 of the drawings wherein it will be observed that-greater volume of drying air directed downwardly onto the selvage edge portions of the fabric inwardly adjacent the tenter chains Ill operates to deflect the `fabric downwardly at a small angle which serves to prevent the fabric from becoming disengaged from the tenter pins l. On the other hand, the greater volume of air directed upwardly against the underside of the central portion of thev fabric I I serves to maintain the central. portionof the fabric elevated in va relativeasc 1,621

ly iioating condition without causing the edge portions of the fabric to be raised to a point where they can be snapped loose and disengaged from the tenter pins I. Furthermore, by effecting a relatively elevated floating condition of the central portion of the fabric II crosswise tension in the fabric due to sagging is eliminated so that substantially slack or tensionless drying of the fabric is accomplished.

Drying air discharged against the fabric II from the upper and lower sets of nozzles 2D and 2| finds its way laterally outward from between the chambers i3 and Ill whence it is drawn upwardly within the housing I through the heating coils 5 where it is reheated and then is Arecirculated by the blower 6 through the duct I5 and branches IS and I'I to the chambers I3 and Iii, respectively.

In lieu of the nozzle opening construction shown in Figs. 4 and 5 of the drawings and previously described herein the nozzle opening construction and arrangement shown in Figs. 6 and 'I respectively may be employed to advantage. For example, as shown in Fig. 6 of the drawings, the upper discharge nozzles 26 may be provided in lieu of a single continuous outlet opening with a series of openings of gradually decreasing area inwardly from opposite ends of the nozzle. wise in lieu of the continuous single opening shown in Fig. '5, the lower nozzles 2I may beY provided with a series of openings of gradually increasing area inwardly from opposite ends ofthe nozzle as shown in Fig. 7.

By the present invention the use of large volumes of drying air at higher velocities may be accomplished to an extent that the capacity or production of tenter dryers of this type may be increased by as much as 20%. At the same time the invention provides a novel nozzle construction and arrangement which is operablel to assist in maintaining the fabric impaled upon the tenter pins while the central portion ofthe fabric may be supported in a relatively elevated floatingr condition to minimize transverse stretch and l. In a. tenter dryer comprisinga housing and av tenter chain movable longitudinally therethrough provided with upstanding pins upon which the opposite selvage edges of a fabric are impaledto convey the fabric through the dryer, a plurality of transversely disposed discharge nozzles for dry ing air uniformly spaced longitudinally of the housing above and below the fabric and constructed to cause substantially larger volumes of drying air to be discharged downwardly at the selvage edge portions of the fabric than .are discharged upwardly against the underside ofsad edge portions to thereby retain the fabric-impaled on the pins and to cause' a substantially larger volume of drying air to be discharged upwardly against the underside of the fabric central portion than is discharged downwardly thereon to thereby support the fabric invan elevated relatively floating condition.

2. In a tenter dryer comprising a housingandia tenter chain movable longitudinally therethrough provided with upstandngpins upon which the Likeopposite selvage edges of a length of fabric are impaled to convey the fabric through the dryer,

a plurality of transversely disposed discharge nozzles for drying air uniformly spaced longitudinally of the housing above the fabric and having outlet openings constructed to discharge larger volumes of drying air downwardly onto the selvage edge portions of the fabric and a lesser volume of air downwardly onto the center portion thereof, and a corresponding plurality of discharge nozzles for drying air similarly arranged below the fabric constructed to discharge lesser volumes of air upwardly against the underside of the selvage edge portions of the fabric and a larger volume of drying air upwardly against the central underside of the fabric, the larger volumes of air discharged downwardly onto the selvage edge portions of the fabric being substantially greater than the lesser volumes of air discharged upwardly against said selvage edge portions to retain said edge portions impaled on the pins and the larger volume of air discharged upwardly against the underside of the fabric central portion being substantially greater than the lesser volume of air discharged downwardly onto the fabric central portion so that the latter is supported in an elevated relatively oating condition between its selvage edges.

3. In a tenter dryer comprising a housing and a tenter chain movable longitudinally therethrough provided with upstanding pins upon which the opposite selvage edges of a fabric are impaled to convey the fabric through the dryer, a plurality of discharge nozzles for drying air uniformly spaced longitudinally of the housing K and extending crosswise above the fabric to discharge air downwardly against the upper surface thereof, a corresponding plurality of discharge nozzles for drying air similarly arranged below the fabric to discharge drying air upwardly against the lower surface thereof, the nozzles above the fabric each having a continuous outlet opening crosswise of the fabric of predetermined maximum width at the opposite ends of said opening and gradually decreasing in width inwardly to a minimum width at the midpoint thereof, and the nozzles disposed below the fabric each having a continuous outlet opening cross-wise of the fabric of predetermined minimum width at the outer ends of said opening and gradually increasing in width inwardly to a maximum width at the midpoint thereof, said nozzle constructions operating to cause substantially larger volumes of drying air to be discharged downwardly at the selvage edge portions of the fabric than are discharged upwardly against the underside of said edge portions to thereby retain the fabric on the tenter pins and causing a substantially larger volume of drying air to be discharged upwardly against the underside of the fabric central portion than is discharged downwardly thereon to thereby support the fabric in an elevated relatively floating condition.

4. In a tenter dryer comprising a housing and a tenter chain movable longitudinally therethrough provided with upstanding pins upon which the opposite selvage edges of a length of fabric are impaled to convey the fabric through the dryer, a plurality of transversely disposed discharge nozzles for drying air uniformly spaced longitudinally of the housing above the fabric and each having outlet openings therein of gradually decreasing area inwardly from opposite ends of the nozzle operable to discharge larger volumes of drying air downwardly onto the selvage edge portions of the fabric and a lesser volume of air downwardly onto the central portion thereof, and a corresponding plurality of discharge nozzles for drying air similarly arranged below the fabric and each having outlet openings therein of gradually increasing area inwardly from opposite ends of the nozzle operable to discharge lesser volumes of air upwardly against the= underside of the selvage edge portions of the fabric and a larger volume of drying air upwardly against the central underside of the fabric, the larger Volumes of air discharged downwardly onto the selvage edge portions of the fabric being substantially greater than the lesser volumes of air discharged upwardly against said selvage edge portions to retain said edge portions impaled'on the pins and the larger volume of air being discharged upwardly against the underside of the fabric central portion being substantially greater than the lesser volume of air discharged downwardly onto the fabric central portion so that the latter is supported in an elevated relatively floating condition between its selvage edges.

5. In a tenter dryer comprising a housing and a enter chain movable longitudinally therethrough provided with upstanding pins upon which the opposite selvage edges of a fabric are impaled to convey the fabric through the dryer, a plurality of discharge nozzles for drying air uniformly spaced longitudinally of the housing and extending cross- Wise above the fabric to discharge air downwardly against the upper surface thereof, a corresponding plurality of discharge nozzles for drying air similarly arranged below the fabric to discharge drying air upwardly against the lower surface thereof, the nozzles above the fabric each having a series of outlet openings crosswise of the fabric of gradually decreasing area inwardly from opposite ends of the nozzle and the nozzles disposed below the fabric each havinga series of outlet openings crosswise of the fabric of gradually increasing area inwardly from the outerends of the nozzle, said nozzle constructions operating to cause substantially larger volumes of drying air to be discharged downwardly at the selvage edge portions of the fabric than are discharged upwardly against the underside of said edge portions to thereby retain the fabric on the tenter pins and causing a substantially larger volume of drying air to be discharged upwardly against the underside of the fabric central portion than is discharged downwardly thereon to thereby support the fabric in an elevated relatively floating condition.

MICHAEL SHEGDA.

REFERENCES CTTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain June 5, 1945 

